论文标题
富达奇怪的相关因子，用于平均对称性保护拓扑阶段
Fidelity Strange Correlators for Average Symmetry-Protected Topological Phases
论文作者
论文摘要
开放量子系统中的拓扑阶段已成为令人兴奋的研究领域，这是由于嘈杂的中间尺度量子平台的重要性驱动的。平均对称性保护拓扑（ASPT）阶段的概念将受对称性保护的拓扑阶段扩展到受障碍或反熔性影响的量子系统。为了识别非平凡的ASPT状态，我们引入了一个“保真性奇怪的相关器”（FSC），该（FSC）直接在没有边界的单个散装密度矩阵上运行。对于一个和二维中的非平凡的ASPT阶段，我们表明FSC揭示了远程或幂律行为。在几个二维示例中，我们在具有量子校正的统计环模型中建立了FSC与某些非本地相关函数之间的联系，从而使我们能够为FSC得出精确的缩放指数。此外，我们讨论了使用经典影子层析成像测量FSC的方法。我们的工作为在开放量子系统中（数值和实验性）中识别物质的这些有趣的拓扑阶段奠定了基础。
Topological phases in open quantum systems have become an exciting area of research, driven by the rising importance of noisy intermediate-scale quantum platforms. The concept of Average Symmetry-Protected Topological (ASPT) phases extends symmetry-protected topological phases to quantum systems affected by disorder or decoherence. To identify nontrivial ASPT states, we introduce a "fidelity strange correlator" (FSC), which operates directly on a single bulk density matrix without boundaries. For nontrivial ASPT phases in one and two dimensions, we show that the FSC reveals long-range or power-law behavior. In several two-dimensional examples, we establish a link between the FSC and certain non-local correlation functions in statistical loop models with quantum corrections, enabling us to derive exact scaling exponents for the FSC. In addition, we discuss methods to measure the FSC using classical shadow tomography. Our work lays the groundwork for identifying these intriguing topological phases of matter in open quantum systems, both numerically and experimentally.
